The purpose of the project is to develop a catheter system for interventional radiology capable of traversing small and branching blood vessels (i.e., 1.5 to 4.0 mm) to reach the proximity of tumors and to administer chemotherapeutic drugs to these tumors in a controlled manner. A major obstacle to effective treatment is thought to be maldistribution of the drug at the site due to inadequate mixing of the drug with the blood. A revised version of the multilumen catheter previously reported has been developed that has greatly simplified the use of the jet principle for mixing. Fluid turbulence generated by drug emanating at retrograde angles from the tip of the catheter adds significantly to the mixing of the drug within the blood stream.